Hi! I am considering reporting my ex boyfriend for tax fraud. He and his cousin have a "business" buying medical equipment and reselling it. They each make approximately $12,000-15,000 a year doing this, and do not claim it as income. Is it enough $ for the IRS to even care? There are no records of this business other than checks written out of and deposited into his bank accounts. Would that be enough proof? Any knowledge would be appreciated.